Phosgene, COCl2, is a colorless, highly toxic gas which has been used in chemical warfare, notably in World War I, as well as in industrial processes including the making of dyestuffs and polyurethane resins. When inhaled, phosgene reacts with water in the lungs to form hydrochloric acid and carbon monoxide. The release of hydrochloric acid into the lungs causes pulmonary edema and may also cause bronchial pneumonia and lung abscesses, which in severe cases may result in death within 36 hours.
Conducting polymers, such as polyaniline, have been widely studied as chemical sensors due to their simple and reversible acid doping and base dedoping chemistry. Polyaniline is a conducting polymer that has been widely studied for electronic and optical applications. Unlike other conjugated polymers, polyaniline has a simple and reversible acid doping and base dedoping chemistry enabling control over properties such as free-volume, solubility, electrical conductivity, and optical activity. In recent years, one-dimensional polyaniline nanostructures, including nano-wires, rods, and tubes have been studied with the expectation that such materials will possess the advantages of both low-dimensional systems and organic conductors. The change in conductivity associated with the transition from the insulating emeraldine base to the conducting emeraldine salt form of polyaniline is over ten orders of magnitude. This wide range in conductivity has been utilized to make polyaniline sensors that can detect either acids or bases. Polyaniline is one of the most widely studied conducting polymers because of polyaniline's environmental stability and straightforward synthesis. Polyaniline is a useful material for chemical sensors because polyaniline conductivity can change in the presence of doping and dedoping agents. In the undoped state, insulating emeraldine polyaniline is an interesting material for chemical sensors because the conductivity can increase by over ten orders of magnitude on exposure to doping acids. This process can be reversed by dedoping in the presence of bases.
It would be useful to be able to provide a chemical sensor for detecting phosgene using a conductive polymer such as polyaniline and/or a nanofiber material.